Gasometer construction



GASOIETER CONSTRUCTION Fiied, June 1, 1937 2 Sheets-Sheet 1 FIGJ.

INVENTOK JAMES $.MALSBARY ATTORNEY.

March 1940' J. 5. MALSBARY GASOIETER CONSTRUCTION Filed June 1, 1937 2 Sheets-Sheet 2 PIC-3.3.

INVENTOR. JAMES SMALSBARY BY g ATTORNEY.

Patented Mar. 26, 1940 PATENT OFFICE.

GASOMETER WNSTBUUHON James 8. Malsbary, Kirkwood,.Mo., assignor to Wagner Electric Corporation, St. Louis, Mo., a corporation of Delaware Application June 1, 1931, Serial No. 145,177

2Claims.

My invention relates to apparatus for maintaining a supply of inert gas in a gas containing space above the fluid level in oil-filled" transformer tanks and other liquid containing tanks in which it is desirable that the space above the liquid should be filled 'with inert gas (nitrogen or carbon dioxide, for example) rather than with air. As herein illustrated, my invention is applied to a type of gasometer construction, for the pur- 0 pose indicated, which comprises a gas chamber formed by a rigid casing portion and a flexible inflatable bag portion, which bag carries a weight determining the inert gas pressure which will be maintained. Gasometers of this type are described in the prior application of Hans Weichsel, Serial No. 144,321, filed May 22, 1937 and it is one of the special objects of this invention to provide means which will reduce to a minimum the amount of inert gas lost during the operation of a transformer with which such apparatus is associated. Other objects of the invention appear from the following description.

In the accompanying drawings Figure 1 is a view, partly in section and partly in elevation,

illustrating a gasometer and associated apparatus embodying my invention; Figure 2 is a diagrammatic view illustrating my improved control mechanism for the supply of gas to the gasometer; and Figure 3 is a detail view illustrating means for protecting the gasometer bag from injury during shipment of the gasometer.

Referring to Figure 1, an oil-filled transformer is shown which consists of a casing element l. a transformer 2 and'a body of oil submerging the transformer, the oil level indicated being assumed to be that existing when the transformer is in operation under temperature conditions lower than the highest which may exist. The gas space 3 of the transformer is in communication through pipe 4 with the gas chamber 5 of the gasometer. This gas chamber is formed by the rigid casing element 6 (preferably cylindrical) and a flexible inflated bag element 1 which may be formed of synthetic rubber composition such as marketed under the trade-names Duprene and Thiokal".

The outer upper surface of the bag element 1 carries a. weight element I having a cylindrical extension fla forming a support for the inner surface of the torus portion of the bag element which lies between this extension and the inner wall of the top protective casing element 9 throughout a substantial part of the range of movement of the weight contacting portion of the bag during operation; Numeral ill represents a gas supply tank containing inert gas under high pressure which communicates with the gasometer chamber through pipe ll under control of a known form of pressure reducing valve l2 and a gas shut-off valve l3.

The top of the transformer casing is provided 5 with a purge valve 15 and with a safety valve i6 which limits the pressure which could be developed in the gas space of the transformer under any condition of operation. As will be later brought out, however, the object of my invention 10 is to normally prevent weight element 8 from reaching the upward limit of its movement and, therefore, to prevent the development of any greater pressure in the transformer gas space than that determined by the value of the weight 1 in relation to its area. I do not claim as my invention the construction thus far described, the same being illustrated in the co-pending application of Hans Weichsel heretofore identified.

The top portion of easing 9 is provided with so stop posts H welded through and preferably spaced about degrees apart. These stop posts limit the upward movement of the bag element, being in the path of movement of weight 8.

Before referring in detail to the gas supply con- 25 trol apparatus constituting my invention, reference may be made to the fact that in the operation of a transformer change in load or in surrounding temperature conditions will cause a rise or fall of the oil level in the transformer and, 3 therefore, a reduction or increase in the volume of gas containing space 3. However, neither increase nor decrease of this space will change the gas pressure therein unless the weight element of the gasometer bag is at the time at one end or 35 the other of its path of travel. Under other conditions, the weighted portion of the gasometer bag 8 will either rise or fall, depending upon whether the gas -space in the transformer has increased or diminished or the temperature of the 0 inert gas has changed, and the pressure will remain the same.

The purpose of my control mechanism is to provide means whereby the weight element of the bag will not, under normal range of operat- 45 ing conditions, reach its upward limit of movement and, therefore, whereby there will be no waste of gas other than that resulting from joint leaks in the gas space of the gasometer or transformer. If, when gas is introduced into the 50 gasometer from tank ll, it is permitted to continue to flow in until the weight is brought against posts ll before being cut off, subsequent increase in transformer temperature might result in sufiicient increase in gas pressure 55 to open safety valve l8 and permit waste of gas. My improved control mechanism for avoiding this condition will now be described.

To the cover I! or to the upper part of the .top casing element of the gasometer, is attached a switch control mechanism indicated in outline at It in Figure 1, said switch mechanism being for the purpose of controlling the circuits by means of which gas supply valve I3 is operated. These circuits are illustrated in Figure 2.

The switch mechanism referred to comprises an arm l9 carrying a mercury switch Ml. Spring 2| tends to hold the arm in its top position against stop 26, as indicated in full lines in Figure 2. One end of spring 22 is attached to arm l9 and the other end to a chain 23 of suitable length which is connected to weight 8 of the gasometer. A spring 24 is also provided, one end of which is connected to arm I 9 and the other to a fixed point so located, as indicated in Figure 2, that it tends to snap the switch arm I! downward against stop 25 after the arm has been brought past horizontal position by tension on chain 23 and spring 22 under the conditions to be hereafter mentioned.

Referring to operation of the control apparatus Just described, the length of chain 23 and spring 22 is so chosen that when, due to fall in temperature of the transformer or to leak of gas, the weight element 8 reaches a predetermined position, such for example, as indicated by the dotted line 21 in Figure 1, switch arm 19 will have been brought below horizontal whereupon spring 24 will snap the arm' to the position shown in dotted lines in Figure 2. As shown in full lines in this figure, the mercury of switch does not connect the contacts to close the circuit by means of which solenoid 28 is energized through a battery or other source of current 29, but when the switch arm is in the dotted line position, these contacts are connected by the mercury and the solenoid opens gas supply valve l3 permitting gas to iiow into the gasometer chamber through pipe II from tank Hi. When the gasometer weight has risen to a point where tension on spring 22 is sufllciently reduced, spring 2| returns the switch arm to the full line position whereupon solenoid 28 is deenergized and spring 30 closes valve 13. The relation is so chosen that the action just described occurs when the gasometer weight has risen to approximately the position indicated in full lines in Figure 1, and, consequently, even though there is considerable rise in temperature of the transformer above that existing at the time the gas supply valve is closed, the weight will not be brought to the upper limit of its movement against stops l4 and, therefore, no excess pressure will be built up which might result in opening safety valve l6 and discharging gas to the atmosphere.

It is to be observed that by the employment of my invention the gasometer apparatus can be designed to automatically admit gas from the gas storage tank if only a small loss has occurred and to supply only a small quantity at a time. Therefore, the apparatus can be extremely economical in operation since no inert gas would be lost except to the extent of gas leaks which may be permitted to continue through neglect, and also the size of the gasometer can be much smaller than if gas is admitted and cut 011 only at limits of possible movement of the weight.

Since the inflatable bag employed in the apparatus of the character described is of light material which could be damaged by a heavy weight 8 during shipment of the apparatus if said weight were permitted to move, means must be provided to secure this weight in position at this time and this is facilitated by the provision of stop posts I whereby during shipment rod I can be applied which is threaded at one end into the weight, the upper end is secured to the top casing of the apparatus as shown in Figure 3, and the weight is clamped firmly against the ends of the stop posts.

Being aware of .the possibility oi. modifications in the particular structure herein described without departing from the fundamental principles of my invention, I do not intend that its scope be limited except as set forth by the appended claims.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In gasometer apparatus comprising a gas chamber provided with a wall part movable to vary the volume of the chamber, a source of gas under pressure connected to said chamber and a gas shut-off valve in said connection, control means for said valve comprising an electric circuit and a switch element for opening and closing said circuit, said switch element being biased to open position by a spring and also connected by spring means to the movable part of the gas chamber, said second spring being proportioned to overcome the biasing spring and move the switch. arm toward closed position upon movement of the chamber wall to a predetermined position, and means efiective when the switch arm has been moved a predetermined distance from open position to cause said arm to snap to switch-closed position.

2. A gasometer apparatus for the purpose described comprising a gas-tight container having a portion of its wall formed of flexible material, a weight element supported by said wall, means limiting'the upward movement of said weight element, a gas supply source connected to said container, a gas shut-off valve for said connection, a control element for said valve, a spring tending to maintain said control element in open position, a second spring stronger than said first mentioned spring and connected to said control element and to the weight for moving said element toward closed position when the weight by its downward movement applies sufficient force to said second mentioned spring to overcome the resistance of the first mentioned spring, and a third spring element acting in cooperation with the second spring and against the first spring when the control element has been moved to a predetermined position from open position and functioning to quickly bring the control element to closed position. v

JAMES S. MALSBARY. 

